I have a Ten year old Mark IV widebody combo that I bought new and never had a problem with until now. When playing it shuts of momentarily....lights go out for a second or maybe a fraction of a second and then come back on. The sound does not change or get crappy, the amp just shuts down and sound cuts out. I changed the power tubes and the fuse but no luck. It does it hot or cold, sometimes not for hours (I played it for 5 hours last saturday and it never shut down) then other times 2 or 3 times in a couple minutes. I called Boogie and was told it must be a bad connection somewhere. Anyone ever have a similar problem? Any suggestions? It happens so intermittently I hesitate to bring it in to the repair shop, they might not be able to find anything when it's behaving.
Mark IV intermittent Failure
- Thread starter phittel
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Boogiebabies
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You whole preamp and switching system rely on two 10,000uf 16V caps for the 12V and 15V switching voltage. The controllers rely on
a voltage regulator (7805) to lower the 12V to 5V. If the caps are intermittently not charging or the voltage regulator overheats and resets, it could
cause the problem you are describing. You may want to pull the chassis and see if those two caps are bulging at the top and leaking yellow goo.
a voltage regulator (7805) to lower the 12V to 5V. If the caps are intermittently not charging or the voltage regulator overheats and resets, it could
cause the problem you are describing. You may want to pull the chassis and see if those two caps are bulging at the top and leaking yellow goo.
The way you describe it, it sounds like the power cuts *completely*, right? First thing I'd do is try a different power lead from another appliance, the lead could have developed a breakage inside it from years of use & abuse. Also try and see if you can reproduce the fault by moving the power cable around, especially towards the ends. If it makes no difference, then you can rule this out.
HTH
HTH
